Field of the Invention
The present invention relates to a piezoelectric speaker and electroacoustic transducer that can be applied to earphones, headphones, mobile information terminals, etc., for example.
Description of the Related Art
Piezoelectric speakers are widely used as a simple means for electroacoustic conversion, where popular applications include earphones, headphones and other acoustic devices as well as speakers for mobile information terminals, etc., for example. Patent Literature 1 discloses a piezoelectric speaker constituted by a vibration plate made of metal material and a piezoelectric element joined to it.
A piezoelectric speaker having the above constitution can generate sound waves according to the playback signals input to the two external electrodes of the piezoelectric element, by causing the vibration plate to vibrate based on the playback signals.    [Patent Literature 1] Japanese Patent Laid-open No. 2013-150305